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Cell Mol Life Sci

Title:		Biochemical characterization and bacterial expression of an odorant-binding protein from Locusta migratoria
Author(s):		Ban L; Scaloni A; D'Ambrosio C; Zhang L; Yahn Y; Pelosi P;
Address:		"Department of Entomology, China Agricultural University, Beijing, China"
Journal Title:		Cell Mol Life Sci
Year:		2003
Volume:		60
Issue:		2
Page Number:		390 - 400
DOI:		10.1007/s000180300032
ISSN/ISBN:		1420-682X (Print) 1420-682X (Linking)
Abstract:		"Analysis of soluble proteins from different body parts of Locusta migratoria revealed a fast-migrating component in native electrophoresis, unique to antennae of both sexes. N-terminal sequence analysis and cloning identified this protein as a member of the insect odorant-binding proteins, carrying a well-conserved six-cysteine motif. Mass spectrometry analysis confirmed the occurrence of two distinct polypeptide species determined by nucleotide sequencing and demonstrated that the cysteine residues are paired in an interlocked fashion. The protein was expressed in a bacterial system with yields of about 10 mg/l of culture, mostly present as inclusion bodies. However, this recombinant product was solubilized after disulfide reduction. Air oxidation yielded a species with all disulfides spontaneously formed as in the native counterpart. Both native and recombinant proteins migrated as a dimer in gel filtration chromatography. Ligand binding was measured, using N-phenyl-1-naphthylamine as the fluorescent probe; the affinity of other ligands was measured in competitive binding assays. The protein exhibited great resistance to thermal denaturation even following prolonged treatment at 100 degrees C. A structural model for this dimeric species was generated on the basis of its sequence homology with Bombyx mori pheromone-binding protein, whose three-dimensional structure has been resolved as an unbound species and in complex with its physiological ligand. This is the first report of an odorant-binding protein identified and characterized from Orthoptera"
Keywords:		"Amino Acid Sequence Animals Binding, Competitive Dimerization Disulfides/analysis Escherichia coli/genetics Female Hot Temperature Inclusion Bodies/metabolism Insect Proteins/*chemistry/*metabolism Ligands Male Models, Molecular Molecular Sequence Data Mo;"
Notes:		"MedlineBan, L Scaloni, A D'Ambrosio, C Zhang, L Yahn, Y Pelosi, P eng Comparative Study Research Support, Non-U.S. Gov't Switzerland 2003/04/08 Cell Mol Life Sci. 2003 Feb; 60(2):390-400. doi: 10.1007/s000180300032"